The interesting thing is how even the instructions related to the cart work cast doubt on the WT stance.
This is from the KM 7/13...
6 Public Witnessing That Is Organized Locally: In addition to special metropolitan public witnessing, another new initiative is being organized by many bodies of elders in their local territory. With this initiative, publishers use a table or a mobile display at a busy location within the congregation’s territory boundary. This is different from special metropolitan public witnessing, which uses participants from many congregations to preach in the same high-traffic areas in cities chosen by the branch office.—See the box “Good Cooperation Needed.”
7. Where it is practical, how will the elders organize public witnessing locally?
7 The elders will consider whether the congregation’s territory has areas of high pedestrian traffic and determine if it would be practical to organize public witnessing. Possible locations for a table or mobile display include transportation hubs, public squares, parks, busy streets, shopping malls, college campuses, airports, and locations of annual events. There is an advantage in having a table set up in the same location, on the same days, and at the same times. It has been found that tables set up at shopping malls are more effective than those outside a single large store where individuals are usually focused on their reason for visiting that specific store. Some locations, such as busy sidewalks, may be more conducive to a smaller mobile literature display. Elders can download from our Web site special files for making displays of the Watchtower and Awake! magazines and the Bible Teach book. These files have been prepared specifically for use in this form of public witnessing. Those who participate will carry out the work in much the same way as those engaged in special metropolitan public witnessing and should follow the direction of the service overseer closely. If they obtain an address from an interested person who does not live in their territory, they should promptly fill out a Please Follow Up (S-43) form and give it to the secretary.
Note how this is organised by the elders (i.e. the congregation). The next bit is also telling...
8. If there are no organized efforts in the congregation for public witnessing, what opportunities to preach publicly may still be available?
8 Public Witnessing in Your Personal Ministry: Some congregations may not have a location in their territory that has sufficient pedestrian traffic to justify setting up a table or making use of a mobile literature display. However, even in those congregations, publishers are encouraged to consider including public witnessing in their personal ministry. Is there a shopping area, a strip mall, or a busy store in your territory? Is there a park or a place where people gather? Are there public events that are periodically held in the territory? If so, you may still be able to enjoy public witnessing.
Note how the personal ministry does not even include the carts and is not organised by the congregation.
Double speak at it's best.